1. Field of the Invention
The present invention relates to a stick type cosmetic material feeding container which feeds out a stick type cosmetic material for use.
2. Description of the Related Art
Japanese Patent Laid-Open Publication No. Hei 11-146808 (JPA11-146808) shows a typical method for moving a stick type cosmetic material forward and backward by rotatably connecting a front cylinder and a container body, retaining the stick type cosmetic material at a cosmetic material retaining section which is provided at a tip of a push rod internally installed, and rotating the front cylinder and the container body described above. This method is shown as a conventional example in FIGS. 8 and 9.
In the stick type cosmetic material feeding container shown in FIG. 8, a front cylinder 231 and a container body cylinder 241 are connected coaxially and rotatably. A push rod 251 is installed therein. A cavity section 253 is provided at a tip of the push rod 251, and a stick type cosmetic material 233 is retained at the cavity section 253.
A longitudinal engagement groove 237 is formed in the front cylinder 231. Projections 257 formed on a surface of the push rod 251 are engaged with the engagement groove 237, thereby constituting a rotary stop mechanism. Further, on the side of the container body, the projections 257 are spirally engaged with a female screw section 245, thereby constituting a spiral engagement mechanism.
When the front cylinder 231 and the container body cylinder 241 are rotated in such a state, the push rod 251 advances while rotating synchronously with the front cylinder 231. Thus, the stick type cosmetic material starts projecting from a tip opening 235.
Further, in the stick type cosmetic material feeding container shown in FIG. 9, a female screw section 261 is provided at a base end of the front cylinder 231 An engagement groove 265 which is engaged with the projections 257 of the push rod 251 in a vertical direction constitutes a rotary stop mechanism in the container body cylinder 241. The female screw section 261 described above and the projections 257 of the push rod 251 which are spirally engaged with the female screw section 261 constitute a spiral engagement mechanism.
Thus, in FIG. 9, the push rod 251 and the front cylinder 231 are rotated relatively to each other and the stick type cosmetic material 233 advances while rotating with respect to the front cylinder 231.
However, in the stick type cosmetic material feeding containers shown in FIGS. 8 and 9, the stick type cosmetic material is retained at the tip cavity section 253 of the push rod 251. A space for the tip cavity section 253, which is equivalent to a thickness of the push rod 251, is provided in the front cylinder 231.
Therefore, when the stick type cosmetic material is, for example, warped due to heat or a change of dead weight, in FIG. 8, a load on the stick type cosmetic material is relatively light because the stick type cosmetic material advances without rotating in the front cylinder. However, when the front cylinder and the stick type cosmetic material advance while rotating relatively to each other as shown in FIG. 9, the stick type cosmetic material in a state of being warped comes into contact with an inner circumferential surface of the front cylinder while making a rotation, whereby the stick type cosmetic material is easily broken or chipped off.
As shown in FIG. 9, the stick type cosmetic material feeding container in which the stick type cosmetic material advances while rotating with respect to the front cylinder has the effect of creating a high-grade atmosphere by giving a molding core of lipstick a cubic effect. In particular, a stick type cosmetic material of a small bore diameter has an advantage of being three-dimensional for the reason described above, but such a stick type cosmetic material is hardly utilized under the existing circumstances.
An object of the present invention is to provide a stick type cosmetic material feeding container in which a stick type cosmetic material advances while rotating relatively to a front cylinder, but the stick type cosmetic material keeps standing up straight in the front cylinder. Thus, there is a lesser possibility that the stick type cosmetic material might be broken or chipped off at the time of use.
In order to achieve the object described above, a stick type cosmetic material feeding container according to the present invention comprises a front cylinder having an opening hole at its tip, a container body to be coaxially and rotatably connected to the front cylinder, a push rod which is provided in these front cylinder and container body and at the tip of which a cosmetic material retaining section for retaining a stick type cosmetic material is formed, a spiral engagement mechanism formed between the push rod and an inner circumference of the front cylinder, and a rotary stop mechanism formed between the push rod and the container body, wherein a feeding mechanism for causing the stick type cosmetic material to go in and out through the opening hole of the front cylinder by moving the push rod in an axial direction due to rotations of the front cylinder and the container body is provided, a spiral groove is formed at an inner circumference of the front cylinder so as to constitute the spiral engagement mechanism, and the cosmetic material retaining section is constituted by a spiral piece which extends in a helical shape from a tip of the push rod and is spirally engaged with the spiral groove.
In an aspect of the present invention, the spiral groove in the front cylinder comprises a single line of groove and also the spiral piece provided at a tip of the push rod comprises a single line of spiral piece with the same pitch as that of the spiral groove and a stick type cosmetic material is stored and retained in a space inside the spiral piece.
In another aspect of the present invention, the push rod is furnished with a spiral engagement section with the same pitch as that of the spiral piece in such a manner that the spiral engagement section is lined with the spiral piece provided at a tip of the push rod, and the spiral engagement section and the spiral groove of the front cylinder are spirally engaged, thereby constituting the spiral engagement mechanism described above.
In yet another aspect of the present invention, the push rod is furnished with a projection on an extension line of a spiral of the spiral piece which is provided at a tip of the push rod, and the projection and the spiral groove are spirally engaged, thereby constituting the spiral engagement mechanism described above.
In yet another aspect of the present invention, the length of the spiral groove in an axial direction which is provided in the front cylinder is set to be longer than a shifting stroke of the push rod.
In yet another aspect of the present invention, at an outer circumference of the spiral piece provided at a tip of the push rod, there are provided diameter expansion preventing means for preventing the expansion of an inside diameter of the cosmetic material retaining section which is in contact with a bottom of the spiral groove and is formed inside the spiral piece.
Thus, according to the present invention, in a kind of stick type cosmetic material feeding container in which a stick type cosmetic material core advances while rotating with respect to the front cylinder, since the spiral piece which constitutes the cosmetic material retaining section is engaged with the spiral groove of the front cylinder, the inside diameter of the cosmetic material retaining section, namely, a gap between the outside diameter of the stick type cosmetic material and an inner circumference of the front cylinder at which the spiral groove is formed can be extremely small. As a result, it is possible for the stick type cosmetic material to advance while sliding in the front cylinder with a minimum space left between the stick type cosmetic material and an inner circumferential surface of the front cylinder. Thus, it is possible to prevent an accident which may occur due to a warp of the stick type cosmetic material or the like.
Further, a line of spiral groove is formed in the front cylinder, and a line of spiral piece with the same pitch as that of the spiral groove to be spirally engaged with the spiral groove is formed at a tip of the push rod. Thus, it is particularly effective in making the pitch, which is a shifting distance at the time of a single rotation, smaller.
Further, the spiral engagement section constitutes the spiral engagement mechanism by engaging with the line of spiral groove of the front cylinder subsequently to the spiral piece at the time of rotations of the push rod and the container body. Therefore, no stress is imposed on the spiral piece other than a stress to support the stick type cosmetic material, thereby enabling the stick type cosmetic material to stably advance and retreat in the front cylinder.
Further, since a projection is installed on an extension line of the spiral piece which is provided at a piece of the push rod and constitutes the cosmetic material retaining section and the spiral engagement mechanism is constituted by spirally engaging the projection with the spiral groove provided in the front cylinder, it is comparatively easy to manufacture the push rod.
Further, preventing means are provided at an outer circumference of the spiral piece so that even though the stick type cosmetic material is inserted in the cosmetic material retaining section which is constituted by the spiral piece provided at a tip of the push rod, the inside diameter of the cosmetic material retaining section is not expanded more than its actual dimension. Thus, the inside diameter of the spiral piece will never be expanded more than the planned dimension.
Further, it is set such that the length of the spiral groove in an axial direction provided in the front cylinder is longer than a shifting stroke of the push rod. Therefore, even though the stick type cosmetic material is fed out up to the uppermost limit, the spiral piece provided at a tip of the push rod does not come into contact with a spiral termination at a tip of the front cylinder. Thus, it is possible to prevent that the spiral piece is deformed due to a load which may be on when the spiral piece comes into contact with the spiral termination and therefore the stick type cosmetic material comes off. Thus, the stick type cosmetic material can stably be retained.